This registration is your only chance to get the necessary code to download the beta. The beta which will start this Friday is expected to last a couple of weeks prior to the release of the Xbox One and PC versions of the game. While a Xbox Live Gold account is required on the Xbox One, PC players will also be required to have an EA Origin ID as well to participate, but a pre-order of the game isn’t required in order to gain access to the beta.
If you gain access to the closed beta, all accounts on your Xbox One will apparently have access to the beta according to the FAQ. The code being used in the beta will include three game modes and is only a small slice of the content that will be included in the final game. The beta will only support 12 player multiplayer as already announced. Respawn notes that reason for the beta is to help the studio create a better final release product for their fans.
Players only have till February 17 to register for the beta and from what we understand, registration for the beta does not assure that you will get into the beta right away. Players will be added to the beta a little at a time.
Register for the Xbox One & PC Titanfall beta here.